Rock-drilling machine.



NITED STATES PATENT OFFICE.

MANETI-IO CORTES JACKSON, OF DENVER, COLORADO, ASSIGNOR, BAY i ,DIRECTAND MESNE ASSIGNMENTS, TO THE GARDNER ELECTRIC DRILL AND MACHINERYCOMPANY, OF SAME PLACE.

ROCK-DRILLING MAoHlrN-E.

ySIEEtJIlEI(.)AGLVI'ON' part of Letters Patent No. 683,404,datedseptemher 24, 1901. Application led December 20, 1899i. Serial No.741,031. (No model.)

'To @ZZ whom it may concern.-

Be it known that I, MANETHO Coarse .TACK- SON, a citizenof the UnitedStates of America, residing at Denver, in the county of Arapahoe andState of Colorado, have invented certain new and useful Improvements inRock-Drilling Machines; and I do declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and tothefigures of reference marked thereon, which form a part of thisspecication.

My invention relates to improvements in rock-drilling machines adaptedto be operated through the instrumentality of a dexible shaft andelectric motor or other suitable power, my object being to provide amachine of great efficiency, but which shall be operated at a minimumcost. I attain these objects by the mechanism illustrated in theaccompanying drawings, in which- Figure 1 is a side elevation of myimproved machine. Fig. 2 is a fragmentary horizontal section takenthrough the same. Fig. 3 is a vertical section taken through the drillmech anisln. Figs. 4 and 5 are cross-sections taken on the lines X X andY Y, respectively, Fig. 3, lookin gin the direction of the arrows. Fig.6 is a top view of the clamp and the slotted plate mounted thereon andforming a support for the guide-shell. Fig. 7 is a fragmentary view ofthe crank-shaft, shown partly in section. Fig. 8 is a cross-sectiontaken on the line W W, Fig. 3. Fig. 9 is a cross-section taken on theline Z Z, Fig. 8. Fig. 10 illustrates the supporting-bar, the clamp, andthe guide-shell viewed at right angles to Fig. 1. Figs. 11 and 12illustrate an electric motor and the manner of connectingit with theiiexible shaft.

Similar reference characters indicating corresponding parts in theviews, let the numeral 5 designate the casing of the machine, inclosingthe reciprocating shaft 7, carrying the drill-bit 8, which is secured tothe lshaft by a bolt 9, passing through the shaft and having an openingthrough which the shank of the bit passes. The shaft extremity isprovided with a socket 5, in which the bit is inserted, and an opening5c, through which the bolt passes. (See Fig. 9.) The bolt 9 isemployedto lock the bit in place.` This' is done by tightening the nut 10. Thehead of the bolt 9 is made of sufficient weight to perfectly balance theshaft, whereby there is no tendency of the latter to turn when in anyposition except as it is actuated by the automatic devices hereinafterexplained. -The rear portion of the reciprocating shaft is connectedwith the crank-shaft 12 by a yoke 13, whose front and rear extremities13a and 13c engage the top and bottom of the casing,which is fashionedto accurately guide the same. The front part of the yoke is providedwith an opening through which the reduced portion 'i'a of thedrill-shaft passes. The yoke is open, as shown, to receive the shaftextremity. A space is left between the rear extremity of the drill-shaftand the rear extremity of the yoke to allow the said parts a limitedindependent movement. The portion ofthe drill-shaft located within theyoke is surrounded by a )coilspring 14, one extremity of which engages acollar 15 on the shaft, While the other extremity bears against thefront part 13 of the yoke. The part of the drill-shaft immediatelyforward of the yoke is also surrounded by a coil-spring 16, which islocated between the shoulder 7c of the shaft and the forward extremityof the yoke. These springs 14 and 16 serve asbuers, forming a yieldingconnection between the yoke and the drill-shaft and permitting the yoketo move in either direction independently of the shaft. is an importantfeature. In case the drill-bit gets stuck or fast in the hole the yokecan move `backward in response to the crankshaft without breaking orinjuring the mechanism. Again, if the drill-shaft is moved too close tothe rock the yoke actuated by the crank-shaft may move forward after thedrillbit ceases to move. The rear extremity 13c of the yoke is providedwith a cam-slot 13d,

This

which is engaged by the crank 17 of the shaft.

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made fast to the arms in any suitable man- 1 ner. The sleeve parts 17dof the crank are surrounded by a loose bushing 13, which directlyengages the walls of the cam-slot 13d and forms an antifrictionalbearing between the crank and the yoke. By the peculiar shape of theslot 13d, being an epicycloidal curve, superior thrust or striking poweris obtained. It is so formed that when the crank f first engages theupper or front portion of the slot the entire forward thrust is madewhile the crank is making one-fourth of a revolution, thus impartingabout double the striking force ordinarily obtained by cam or eccentricmechanism. By reason of this #fean ture great striking force may beobtained t even when the crank is rotated at a moderate speed. Moreover,the curve 'of this slot is 1 such as to permita rebound of thedrill-shaft after striking the rock without subjecting` the parts of themechanism to the severe jar or concussion incident to the use of astraight z slot. The peculiar curve of the slot also gives the advantageof requiring a full one-half revolution to the crank in withdrawing thedrill-shaft, giving additional power to withdraw the bit and lesseningthe momentum' during the backward stroke.I It must be unl derstood,however, that while I prefer the peculiarshape of slot shown inthe'drawings and heretofore described the invention is not limited toany special construction of slot.

The crank-'shaft 12 is suitably journaled in the casing. (See Fig. 2.)To one of the projecting extremities of this shaft is made fast` abevel-gear 19, which meshes with a similar gear 20,7to which oneextremity of the exible shaft 2l is secured. The two gears Vare inclosedby a 'dust-proof gear-case 22. To the 'opposite protruding extremity ofthe lcrank-shafti12 is made fast a gear 23,' which meshes with a smallgear or pinion 24, fast on a short shaft V25, journaled on the casing 5and having a fly-wheel 26 made fast to its outer extremity. By thisconstruction and arrangement the speed of the fly-wheel becomes greaterthan that of thecrank-shaft, enabling me toiobtain the desiredvsteadying results and uniformity of mot-ion by the use of a muchsmaller ily-wheel than could otherj wise be employed. This is animportant feature in` a Vmachine of vthis class, `since the space inwhich themachine must be oper- `ated Vis nearly always limited, and alarge Iiywheel, if not prohibitive, becomes a source of great annoyance.As shown in the drawings, the iiy-Wheel is provided with an interiorflange which conceals its operating-gearand pinion. The extremity of theiie'xible shaft 21 remote from the gear 2O is connected with an electricmotor 27 lby a belt 28, e-ngaging pulleys 30 and 3l, respectively,mounted on the motor-shaft 27'a and a short shaft 29, withwhichtheextremity of theiexible shaft is directly'connected. The pulley3O isreadily detachable, whereby the uniformity of the drill-shaft stroke maybe preserved re formed integral with the casing.

gardles's of the revolution or speed of the motor or the voltage of thecurrent with which the motor is connected. This is an important feature,since when working in different localities currents of different voltagemust necessarily be utilized, but by using pulleys 'of various sizes theuniform rapidity "of stroke may be maintained. This belt connection issufficiently positive for all practical purposes and at the same timeprevents breaking or injury to the mechanism in case the movement of thecrank-shaft should be suddenly arrested. It must be understood, however,that any other suitable connection 'between the motor and flexible shaftmay be employed, also that vany desired power other than an electricmotor may be utilized for operating thema-chine.

The mechanism for imparting the rotary movement to the drill-shaft Awillnow be described. `This shaft is provided with a spiral or inclinedgroove A anda straight groove B, the one beingindicated by full linesand the other by dottedlines in Fig. 3. The 'drillshaft is surrounded bytwo ratchet-wheels 32 and 33, inclosed by keepers 34. and 35,10- catedwithin the casing 5 'and locked against rotation th'erein. These twokeepers are located between rings 36 and 37, surrounding the drill-shaft'and formed integral with the casing. These rings lock the keepers andtheir ratchet-wheels against longitudinal movement in the casing. Thekeepers and their respective ratchets are separated by a washer 38. Theratchet 32 is locked against rotation in the direction indicated bythearrow in Fig. 4L by spring-held dogs 39, pivotally mounted'on the keeper3-l. The ratchet 33 is lockedagainst rotation in the same direction bysimilar dogs 40. The ratchet 32 isprovided with a lug 4l, which engagesthe spiral-groove A of the drillshaft. The ratchet 33 is provided with asimilar lug 42, engaging the straight groove B of the drill-shaft. Henceas the said shaft is moved forward in the performance of its function itmoves in a direct line, since the dogs 40 and the ratchet 33 lock itagainst rotation in the direction indicated by the arrouT in Fig. 5 byvirtue of the engagement of the lugv 42 with the straight groove of 'theshaft. Again,during the backward stroke the drill-shaft turns in thedirection opposite that indicated by the arrows in Figs. 4 and 5, sincethe dogsk 39 lock the ratchet 32 against movement in the direction o fthe arrows and the shaft turns by virtue of the engagement ofthe lug 4lwith its spiral gQCWe',

The drill-casing 5 is slidingly mounted -on a guide-shell 43, in whichis journaled the feed-screw 44, engaging a depending nut 45, The turning of the feed-screw bymeans 'of a handcrank 45 causes the casing 5 andits attachmentstomove back and forth on the shell, a'sgdesired'.

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The bottom rof the guide-shell sfprovide'd" Y with a dependingprojection 46, grooved to receive and retain a plate 47, which rests ona clamp member 48, cooperating with a clamp member 49. The two clampmembers are hinged at 50 and embrace the supporting-bar 51. They arelocked on the shaft by a bolt 52, fastened by a nut 53. This bolt alsopasses through a projection 47c of the plate 47. This plate is providedwith a slot 47a, through lwhich passes a bolt 54, whose head engages agroove in the bottom of the plate and is larger than the width of theslot. The depending part 46 of the guide-shell is connected with thisplate by a bolt 54, passing through an opening in the part 46 and theslot of the plate 47 By loosening the nut 56 on this bolt theguide-shell and the drill mechanism may be shifted laterally, the bolttraveling in the slot 47 a for the purpose of inserting a drill-bit,after which the machine may be returned to its normal position in properalinement with the drill-hole. All this may be accomplished withoutloosening the clamp embracing the bar 51 and without getting the machineout of alinement. If it is desired to adjust themachine to drill in adilferent direction, the nut 53 is loosened.

In the operation of the machine the crankshaft is rotated from the motor27 through the instrumentality of the iexible shaft and the connectionsheretofore described. The operation of the crank-shaft imparts areciprocating movement to the drill-shaft by virtue of the engagement ofthe crank 17 with the slot 13d of the yoke, the drill-shaft beingautomatically rotated in the mannerset forth. The drill-casing is movedback and forth on the guide-shell by the operation of the feedscrew. Theshoulder 45 of the crank 45a engages the end of the guide-shell andprevents the screw from traveling longitudinally when turned to carrythe casing forward, and the collar 44a of the screw prevents thebackward movement of the latter when the casing is traveling rearwardly.The yoke 13 is locked against rotation by tongues C and D, formed on thecasing and engaging counterpart grooves formed, respectively, in the topand bottom of the yoke. 4

Having thus described my invention, what venting the rotation of saidyoke, stops on said shaft to the front and the rear of said slidingconnection and a spring interposed between each stop and saidconnection, substantially as described.

2. In a rock-drilling machine, the combi-I nation with a guide-shell andsuitable drilling mechanism mounted thereon, of a supportingbar, a clampembracing the bar, a plate bolted to the clamp and provided with a slotextending parallel with the bar, the guide-shell being provided with adepending part having an opening registering with the slot in the plate,and a bolt passing through the said opening and the said slot, the boltbeing secured by a nut so that by loosening the nut the guide-shell andthe machine supported thereon, may be shifted in a direction parallelwith and independently of the supportingbar without loosening the clampon said bar.

3. In a rock-drilling machine, the combination with a guide-shell and asuitable drilling mechanism mounted thereon, of a supporting-bar, aclamp embracing the bar, a plate bolted to the clamp and provided with aslot extending parallel with the bar, and a groove extending parallelwith but larger than the slot, a part mounted on the guideshell andcooperating with the plate, the said part having an opening registeringwith the slot of the plate, and a bolt passing through the slot and theopening in the cooperating t ioned to interlock with said plate andslide` thereon, the aperture in the shell part registering with the slotin the plate.

5. In a percussive drill, the combination of an inclosing shell, adrill-shaft guided therein, a sliding yoke having a resilient connectionwith the drill-shaft, and a crank-shaft mounted in the shell andconnected to said yoke by means of a slot therein, said slot beingcurved as described to permit the crank to impart a quick forwardmovement and a relatively slow retractile movement to the yoke anddrillshaft as the crank rotates through the forward and backwardstrokes, respectively.

In testimony whereof I ax mysignature in presence of two witnesses.

MANETI-IO CORTES JACKSON.

XVitnesses: Y

A. J. OBRIEN, GRACE MYTINGER.

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